Valve and actuator assemblies

ABSTRACT

The present application relates to valve and actuator assemblies. The valve actuator assemblies may include a capless valve actuating arrangement, include a replaceable passage defining member that includes seal members, include a valve member that is assembled in a valve chamber from an end of the valve body that is opposite an end that a piston is assembled in, and/or include a valve member that may be rotated in a valve body without affecting the ability of the valve member to perform its sealing functions.

RELATED APPLICATIONS

The present application claims priority from provisional applicationSer. No. 60/654,917, entitled “Valve Assemblies,” filed on Feb. 22,2005. Provisional application Ser. No. 60/654,917 is incorporated hereinby reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to valve and actuator assemblies.

BACKGROUND OF THE INVENTION

Valves that block an inlet passage, block an outlet passage and open avent passage when in a first state and open an inlet passage, open anoutlet passage and block a vent passage when in a second state aresometimes referred to as double block and bleed valves. One applicationof double block and bleed valves is to select one of a plurality ofsample streams that is routed to a process analyzer.

It is common practice to utilize a single automated process analyzer foranalyzing multiple sample streams. This significantly reduces the costof analyzing gas and liquid process streams in petrochemical plants,refineries and other process-related industries. The sample streams aregenerally transported to an automated valving manifold near an analyzerby tubing or piping. The automated valving manifold is usuallyelectronically controlled to sequentially select and divert individualsample streams to the automated analyzer.

Air actuators are used to operate valves, such as double block and bleedvalves. Typical air actuators include an actuator housing that defines acylinder, a piston disposed in the cylinder, and a cap that closes thepiston in the cylinder and limits axial movement of the piston in thecylinder. Air is selectively provided into the cylinder to move thepiston against a biasing force of a spring. Some air actuators include avisual indicator that is screwed into the cap to indicate the positionof the piston. One such visual indicator includes a plunger that is incontact with the piston. Movement of the piston moves the plunger toindicate the position of the piston. The height of the visual indicatoris typically set for each individual valve.

SUMMARY

One aspect of the present application is a capless valve actuatingarrangement. A capless valve actuating arrangement allows a position ofa piston to be visually inspected. Another aspect of the presentapplication is a valve that allows seal members that facilitate openingand closing of a valve to be easily replaced. One such valve, which maybe a double block and bleed valve, includes a replaceable passagedefining member that includes seal members. The seal members can easilybe replaced by replacing the passage defining member. Another aspect ofthe present application relates to an actuator construction thateliminates the need for a cap over the piston. For example, a valve,which may be a double block and bleed valve, may include a two or morepart valve body that allows a valve member to be assembled in a valvechamber from an end of the valve body that is opposite an end that apiston is assembled in. The piston and the valve member may be connectedtogether to eliminate the need for a cap. Another aspect of the presentapplication relates to a valve that includes first and second co-planarports that are sealed by a valve member regardless of a rotationalposition of the valve member. One such valve includes a valve memberthat can be rotated about an axis and perform double block and bleedseal functions, regardless of the rotational position of the valvemember. For example, the valve member may include a flat surface thatseals against co-planar ports regardless of the rotational orientationof the valve member. These various aspects may be realized in manyalternative embodiments, either individually or in various combinationsand subcombinations thereof. Unless expressly excluded herein all suchcombinations and subcombinations are intended to be within the scope ofthe present invention.

An example of one valve assembly includes a valve body, a valve member,and a passage defining member. The valve body defines a valve chamber.The valve member is disposed in the valve chamber. The passage definingmember defines an inlet passage, an outlet passage, and a vent passage.When the valve member is at the first position, flow between the inletpassage and the valve chamber is blocked, flow between the outletpassage and the valve chamber is blocked, and flow between the ventpassage and the valve chamber is open. When the valve member is at thesecond position, flow between the inlet passage and the valve chamber isopen, flow between the outlet passage and the valve chamber is open, andflow between the vent passage and the valve chamber is blocked.

In one embodiment, the passage defining member defines a wall of thevalve chamber. In this embodiment, the valve member can be placed in thevalve chamber from an end of the valve body that the passage definingmember is secured to. In another embodiment, all of the walls of thevalve chamber are defined by the valve body.

The inlet passage, the outlet passage, and the vent passage may beopened or blocked in a variety of different ways. In one embodiment, thevalve includes an inlet seal that is fixed with respect to the inletpassage and an outlet seal that is fixed with respect to the outletpassage. In this embodiment, the valve member engages the inlet seal andthe outlet seal when the valve member is in the first position. Thevalve member may comprise an annular disk that engages both the inletseal and the outlet seal. Such an annular disk would selectively openand block the valve passages regardless of a rotational position of thevalve member relative to the valve chamber.

In one embodiment, the vent port is centrally located with respect tothe valve body. For example, an axis of the vent port may be alignedwith an axis of the valve member and/or may be aligned with an axis ofthe valve chamber.

The valve member may carry one or more sealing structures. For example,the valve may include an elongated inlet sealing structure extendingfrom the valve member and an elongated outlet sealing structureextending from the valve member. In one embodiment, the elongated inletsealing structure engages the passage defining member to seal the inletpassage and the elongated outlet sealing structure engages the passagedefining member to seal the outlet passage when the valve member is inthe first position. In another embodiment, the elongated inlet sealingstructure engages a valve body outer surface to seal the inlet passageand the elongated outlet sealing structure engages the valve body outersurface to seal the outlet passage when the valve member is in the firstposition.

The vent passage may be selectively opened and blocked in a variety ofdifferent ways. For example, a vent sealing member may be disposedaround a valve member shaft. The vent sealing member provides a sealbetween the valve member and the valve body when the valve member is inone position to block flow between the valve chamber and the ventpassage. In another exemplary embodiment, an elongated vent sealingstructure extends from the valve member. The elongated vent sealingstructure may engage a valve body inner surface to seal the vent passagewhen the valve member is in the second position.

A capless valve activator can take a wide variety of different forms. Anexample of one such capless valve actuator assembly includes a valvebody, a piston, and a valve member. The valve body defines a pistonrecess in a first end of the valve body and a valve member recess in asecond end of the valve body. The piston is disposed in the pistonrecess. The valve member is disposed in the valve member recess suchthat axial movement of the valve member is limited by the valve body.The valve member is coupled to the piston such that axial movement ofthe piston causes axial movement of the valve member. The axial movementof the piston in the piston recess is limited by the valve member. Inone embodiment, the valve body includes a passage that extends betweenthe piston recess and the valve member recess. In this embodiment, thepiston is coupled to the valve member by a shaft disposed in thepassage.

In one embodiment, the valve member and piston are moveable between afirst position and a second position. The piston may extend past an endof the valve body when the piston and the valve member are in the secondposition. In one embodiment, a portion of the piston that extends pastthe first end of the valve body has a finish that differs from a valvebody finish to provide a visual indication that the valve member and thepiston are in the second position.

In one embodiment, a portion of the piston that extends past the firstend of the valve body includes a circumferential step. The step limitsexposure of a piston seal to foreign objects.

In one embodiment, the passage defining member may comprise a manifoldmember that routes fluid to the inlet passage, fluid away from theoutlet passage, and fluid away from the vent passage. In one embodiment,the passage defining member may comprise a flange member interposedbetween a manifold and the valve body.

In one embodiment of a passage defining member with inlet and outletseal members assembled with the valve flange member, a valve membercontacts the inlet seal member and the outlet seal member to block flow.The valve member is moved to a position where the valve member is spacedapart from the inlet seal member and the outlet seal member to allowflow. The passage defining member and the valve body may be discretepieces. The inlet and outlet seal members may be comprised of o-ringsthat are staked to the passage defining member. The inlet and outletseal members may be replaced by removing the passage defining member andreplacing the passage defining member with a passage defining memberthat includes new inlet and outlet seal members. Annular grooves thataccept the inlet and outlet seal members may be defined in a face of thepassage defining member.

Further advantages and benefits will become apparent to those skilled inthe art after considering the following description and appended claimsin conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a series of double block and bleed valvesin a stream select system;

FIG. 2 is a sectional view taken along the plane indicated by lines 2-2in FIG. 1;

FIG. 3 is a sectional view taken along the plane indicated by lines 3-3in FIG. 1;

FIG. 4 is a sectional view of a valve member blocking an inlet passage,blocking an outlet passage, and allowing flow through a vent passage;

FIG. 5 is a sectional view of the valve illustrated by FIG. 4 with thevalve member positioned to allow flow through the inlet passage, allowflow through the outlet passage, and block flow through the ventpassage;

FIG. 6 is a sectional view of a valve blocking an inlet passage,blocking an outlet passage, and allowing flow through a vent passage;

FIG. 7 is a sectional view of the valve illustrated by FIG. 6 allowingflow through the inlet passage, allowing flow through the outletpassage, and blocking flow through the vent passage;

FIG. 8 is a sectional view of a valve blocking an inlet passage,blocking an outlet passage, and allowing flow through a vent passage;

FIG. 9 is a sectional view of the valve illustrated by FIG. 8 allowingflow through the inlet passage, allowing flow through the outletpassage, and blocking flow through the vent passage;

FIG. 10A is a schematic illustration of a valve with first and secondco-planar ports in an open position;

FIG. 10B illustrates the valve of FIG. 10A in a closed position;

FIG. 11 is a sectional view taken along lines 11-11 in FIG. 10A; and

FIG. 12 is an illustration of a double block an bleed valve mounted to amodular surface mount manifold system.

DETAILED DESCRIPTION

The present application relates to various features of valve andactuator assemblies. These features include, but are not limited to; acapless valve actuating arrangement; a replaceable passage definingmember that includes seal members; assembling a valve member in a valvechamber from an end of the valve body that is opposite an end that apiston is assembled in; and a valve member that may be rotated in avalve body without affecting the ability of the valve member to performits sealing functions. These features are embodied in one or more of thedouble block and bleed valve assemblies 10 illustrated by FIGS. 1-9. Thepresent invention is not limited to the examples illustrated by FIGS.1-9. Double block and bleed valves are but one example of the widevariety valve and actuator assemblies that the features disclosed by thepresent application may be applied to. The features disclosed by thepresent application may be applied to any actuator controlled valve.

FIGS. 1-9 illustrate examples of valve assemblies 10 with a valve member12 that blocks an inlet passage 14, blocks an outlet passage 16 andopens a vent passage 18 when in a first state (See for example FIG. 2)and opens the inlet passage, opens the outlet passage and blocks thevent passage when in a second state (See for example FIG. 3). In theexample illustrated by FIG. 1, the valves 10 are used in a streamselection system 11. The stream selection system controls the valves 10to selectively supply a stream of the selected fluid to an analyzer. Thestream selection system 11 is but one of many applications that thevalves 10 disclosed herein can be used in.

In the examples illustrated by FIGS. 1-9, the valve assemblies 10include a valve body 20, a valve member 12, and a passage definingmember or assembly 22. The valve body 20, the valve member 12 and thepassage defining member or assembly 22 can be made from a wide varietyof different materials. Examples of suitable materials for the valvebody, the valve member 12 and the passage defining member or assembly 22include, but are not limited to stainless steel, carbon steel, alloysteel, monel, hastelloy, titanium, brass, aluminum, inconel, Monel,nickel, Teflon, PCTFE, PEEK, Vespel, and any other structural metal orplastics. It should be readily apparent that appropriate materials forthe components of the valve assemblies may be selected based on theapplication of the valve assembly.

In this application, the term passage defining member encompasses asingle component or a plurality of assembled components. The valve body20 defines a valve chamber 24. The valve member 12 is disposed in thevalve chamber 24, such that the valve member 12 is moveable between afirst position (FIGS. 2, 4, 6, 8) and a second position (FIGS. 3, 5, 7,9). In one embodiment, the passage defining member 22 defines at least aportion of the inlet passage 14, the outlet passage 16, and the ventpassage 18. In other embodiments, the inlet passage, the outlet passage,and the vent passage may not be defined by a passage defining member 22.For example, the inlet passage, the outlet passage, and the vent passagemay be defined by a valve body. In the illustrated examples, the passagedefining member 22 is coupled to the valve body 20 such that the inletpassage 14, the outlet passage 16, and the vent passage 18 are incommunication with the valve chamber 24. Flow between the inlet passage14 and the valve chamber 24 is blocked, flow between the outlet passage16 and the valve chamber is blocked, and flow between the vent passage18 and the valve chamber is open when the valve member 12 is in thefirst position. Flow between the inlet passage 14 and the valve chamber24 is open, flow between the outlet passage 16 and the valve chamber isopen, and flow between the vent passage 18 and the valve chamber isblocked when the valve member is in the second position. In the exampleillustrated by FIGS. 2 and 3, the passage defining member 22 comprises avalve flange member 22 a assembled with the valve body, and a manifoldmember 22 b that routes fluid to and from the valve assembly 10. In theexamples illustrated by FIGS. 4-9, the passage defining member 22comprises a manifold member 22 b secured directly to the valve body 20.The examples illustrated by FIGS. 1-9 illustrate a few of the widevariety of different forms or configurations the passage defining member22 can take.

Referring to FIG. 12, in one embodiment the inlet passage 14 and theoutlet passage 16 exit through an end surface 31 of the passage definingmember or assembly 22. Providing the inlet and outlet passages throughthe end surface 31 allows the valve assemblies to be mounted to asurface mount manifold system 33, including, but not limited to, thesurface mount manifold system disclosed by United States PatentApplication Publication No. 2004/0168732, published on Sep. 2, 2004,titled “Modular Surface Mount Fluid System,” which is incorporatedherein by reference in its entirety. In another embodiment, the purgepassage 18 also extends through the end surface 31 to allow the purgeport to be accessed through a surface mount manifold system. Thefootprint of the valve assembly may be configured to match the footprintrequired by any surface mount manifold system. For example, the size ofthe valve assembly 10 and the spacing and locations of the inlet andoutlet passages 14, 16 may correspond to the footprint required bysubstrate and manifold components of Swagelok's Modular PlatformComponents (MPC) System.

The valve member 12 can take a wide variety of different forms. In theexample illustrated by FIGS. 2 and 3, the valve member 12 includes asealing end portion 30, a piston end portion 32, and an elongated shaft34 extending between the sealing end portion and the piston end portion.In the example of FIGS. 2 and 3, the sealing end portion 30 isdisk-shaped and extends radially outward of the shaft 34. The sealingend portion 30 may include a flat sealing face 36, and a vent portreceiving recess 38. The illustrated vent port receiving recess 38 is acylindrical shaped recess that extends inward from the sealing face 36toward the shaft 34. In the illustrated embodiment, the vent portreceiving recess 38 is axially aligned with a central axis 40 of thevalve member 12. The sealing end portion 30 includes an annular ventseal recess 41. An annular vent sealing member 43 is disposed in therecess 41. A shoulder 42 is formed between the sealing end portion 30and the shaft 34. In the embodiment illustrated by FIGS. 2 and 3, thepiston end portion 32 includes external threads 44.

In the embodiment illustrated by FIGS. 2 and 3, the valve chamber 24 isa cylindrical chamber that is open at a first valve body end 46. Acylindrical piston chamber 48 is disposed in a second valve body end 50.A cylindrical spring chamber 52 is defined in the valve body 20 betweenthe valve chamber 24 and the cylindrical piston chamber 48. An annularshoulder 54 separates the cylindrical recess 48 and the spring chamber52. A frustoconical sealing surface 56 extends from the valve chamber 24to the spring chamber 52. In the illustrated embodiment, the diameter ofthe sealing surface 56 decreases in a direction from the valve chamber24 toward the spring chamber 52. In the illustrated embodiment, anoptional vent 58 is defined in the valve body that extends from anexternal surface of the valve body to the spring chamber 52. A pneumaticcontrol passage 60 is defined in the valve body. The pneumatic controlpassage may be defined in a wide variety of different ways. In theexample illustrated by FIG. 1, the control passage extends from thepiston chamber to the valve body end 46. Pneumatic passage 61 is incommunication with the passage 60 and extends through the flange member22 a to the manifold member 22 b. Pneumatic passage 63 is incommunication with the passage 61 and extends to a pneumatic controlport 65 defined in the manifold member 22 b. In this configuration, thevalve 10 is controlled by selectively applying fluid under pressure tothe port 65 in the manifold member 22 b. In the example illustrated byFIGS. 2 and 3, the pneumatic control passage 60 extends from thecylindrical piston chamber 48 to a pneumatic control port disposed inthe side of the valve body. In the orientation illustrated by FIGS. 2and 3, the pneumatic control passage is positioned at or near the bottomof the cylindrical piston chamber 48.

In the embodiment illustrated by FIGS. 2 and 3, the valve member 12 isdisposed in the valve body, such that the sealing end portion 30 isdisposed in the valve chamber 24, the piston end portion 32 is disposedin the piston chamber 48, and the elongated shaft 34 is disposed in thespring chamber 52. A spring 64 is constrained in the spring chamber 52between the shoulder 42 and the shoulder 54. In the embodimentillustrated by FIGS. 2 and 3, the spring biases the sealing end portion30 in the direction indicated by arrow 66. It should be readily apparentthat the valve body and the spring could be configured to bias the valvemember 12 in the opposite direction. For example, the spring 64 and theshoulder 42 could be repositioned such that the spring is constrainedbetween the piston and the shoulder to bias the piston out of the valvebody.

In the example of FIGS. 2 and 3, the actuating arrangement forselectively moving the valve member 12 between the first position andthe second position is integrated into the valve assembly. It shouldalso be readily apparent that a discrete actuating arrangement may becoupled to the valve to move the valve member between the first andsecond positions. In addition, any type of actuating arrangements couldbe used to move the valve member between the first and second positions.Examples include, but are not limited to pneumatic actuators, hydraulicactuators, and electric actuators.

In the embodiment illustrated by FIGS. 2 and 3, a piston 68 is disposedin the cylindrical recess 48. The piston can be made from a wide varietyof different materials. Examples of acceptable materials for the pistoninclude, but are not limited to stainless steel, carbon steel, alloysteel, monel, hastelloy, titanium, brass, aluminum, inconel, nickel,Teflon, PCTFE, PEEK, Vespel, and any other structural metal or plastics.The piston is connected to the valve member 12. In the exampleillustrated by FIGS. 2 and 3, the piston includes an internally threadedrecess 70 that engages the external threads 44 to connect the piston tothe valve member 12. In the example illustrated by FIGS. 2 and 3, thepiston and the valve member 12 move in the direction indicated by arrow72 against the biasing force of the spring 64 when fluid under pressureis applied to the piston chamber 48. In the example illustrated by FIGS.2 and 3, the valve member 12 limits movement of the piston out of thevalve assembly housing. As a result, a cap is not required to constrainaxial movement of the piston. While the actuating arrangementillustrated by FIGS. 2 and 3 is shown and described with respect to adouble block and bleed valve assembly, it should be readily apparentthat the actuating arrangement could be used with a variety of differenttypes of valve assemblies. For example, the type of arrangementillustrated by FIGS. 2 and 3 could be applied to any valve assembly,that is currently actuated by conventional actuators, including, but notlimited to diaphragm valves.

Referring to FIGS. 2 and 3, the valve flange member 22 a includes a baseportion 74 and a cylindrical vent port protrusion 76 that extends from aan end wall of the base portion. In this example, the valve member isinserted directly into the valve chamber 24 through the first valve bodyend 46 before the flange member 22 a is assembled to the valve body 20.In the illustrated examples, the valve flange member is separate fromthe valve body. The inlet passage 14 and the outlet passage 16 extendthrough the base portion 74. The vent passage 18 extends through thebase portion 74 and the cylindrical vent protrusion 76. The base portiondefines an end wall 78 of the valve chamber. The cylindrical ventprotrusion 76 extends into the vent port receiving recess 38. The baseportion includes an annular valve body seal recess 80. An o-ring 81 isdisposed in the recess 80 to provide a seal between the valve body 20and the flange member 22 a. A seal recess 82 is disposed around an inletpassage opening 83 in the end wall 78 of the valve flange member 22 a.An annular inlet seal member 84 is disposed in the seal recess 82. Forexample, the inlet seal member 84 may be permanently staked in therecess 82. A seal recess 86 is disposed around an outlet passage opening88 in the end wall 78 of the valve flange member 22 a. An annular outletseal member 90 is disposed in the seal recess 86. For example, theoutlet seal member 90 may be permanently staked in the seal recess 86The inlet and outlet seal members are fixed with respect to the inletpassage and the outlet passage respectively. Defining the seal recesses82, 86 in the valve flange member eliminates the need to define the sealrecesses in the valve body. Machining the seal recesses in the valvebody may require inserting a tool through the valve body to reach thesurface where the seal recesses are to be defined. In the embodimentillustrated by FIGS. 2 and 3, when the inlet and outlet seal membersbecome worn or damaged, the inlet and outlet seal members may be easilyreplaced by replacing the valve flange member 22 a of the passagedefining member 22 with a valve flange member that includes new inletand outlet seal members. In another embodiment, the passage definingmember may be a single piece that includes the seal members. The sealmembers may be replaced by replacing the single piece passage definingmember.

In the example illustrated by FIGS. 2 and 3, o-rings are provided toprovide seal between each of the parts of the valve 10. An o-ring 92provides a seal between the piston and the valve body. O-rings 94, 96provide a seals between the valve member 12 and the valve body. Ano-ring 98 provides a seal between the valve member 12 and the flangemember.

FIGS. 2 and 3 illustrate operation of the valve. The spring 64 biasesthe valve member 12 to the position illustrated in FIG. 2. In thisposition, the flat sealing face 36 engages both the inlet seal member 84and the outlet seal member 90 to block both the inlet passage 14 and theoutlet passage 16. In this position, any fluid in the valve chamber 24is open to the vent passage 18. Any fluid that is in the valve chamber24 can escape through the vent passage. In the example illustrated byFIGS. 1-3, a passage 25 is defined in the valve member 12 that allowsfluid to flow from the valve chamber 24 to the vent passage 18 when thevalve member is in the position shown in FIG. 3. When fluid undersufficient pressure to overcome the biasing force of the spring 64 isprovided to the piston chamber 48, the piston and the valve member 12move to the position shown in FIG. 3. The vent seal ring 43 engages thefrustoconical surface 56 to limit axial movement of the piston out ofthe valve member housing. In this position, the flat sealing face 36 isspaced apart from both the inlet seal member 84 and the outlet sealmember 90. Fluid may flow from the inlet passage 14, into the valvechamber 24, and out the outlet passage 16. In this position, the ventseal member 43 provides a seal between the frustoconical sealing surface56 and the valve member 12 to block the flow of fluid from the valvechamber 24 to the vent passage 18. In the example illustrated by FIGS.1-3, the seal between the conical sealing surface 56 and the valvemember 12 prevents fluid flow to the passage 25 to thereby prevent fluidflow to the vent passage 18.

In the embodiment illustrated by FIGS. 2 and 3, axial movement of thevalve member in the direction indicated by arrow 72 is limited by thevalve body. Axial movement of the piston out of the piston recess islimited by the coaction of the valve member 12 and the valve body, sincethe piston and the valve member are coupled together. As a result, thevalve member assembly 12 does not require a cap to limit axial movementof the piston. In the example illustrated by FIGS. 2 and 3, the piston68 is flush with or slightly recessed into the valve body when thepiston and the valve member are in the position illustrated by FIG. 2.In the example of FIGS. 2 and 3, the piston extends past the end of thevalve body when the piston and the valve member are in the positionillustrated by FIG. 3. The portion of the piston that extends past theend of the valve body provides a visual indication that the inlet andoutlet ports are open. In one embodiment, the portion of the piston thatextends past the end of the valve body has a finish that differs from avalve body finish to provide a visual indication of the position of thevalve member and the piston. For example, the piston or a portion of thepiston may be painted to provide an indication of the position of thevalve member and the piston. In the embodiment illustrated by FIGS. 2and 3, the portion of the piston that extends past the first end of thevalve body includes a circumferential step 91 that limits exposure ofthe piston seal to foreign objects. In one embodiment, thecircumferential step 91 includes a wiping ring that inhibitssubstantially all dirt and debris from reaching the piston seal. In theorientation illustrated by FIGS. 2 and 3, the actuation air passage 60is located below the piston and air pressure above the piston does notneed to be maintained. The height of the visual indicator does not needto be set, since the piston itself provides the visual indication.

In the embodiment illustrated by FIGS. 2 and 3, the valve member 12 mayrotate with respect to the valve body 20 without effecting operation ofthe valve 10. When the valve member is in the position illustrated byFIG. 2, the sealing portion 30 will block the inlet passage and theoutlet passage, regardless of the rotational position of the valvemember 12 with respect to the valve body 20. When the valve member is inthe position illustrated by FIG. 3, the vent seal member 43 will blockthe vent passage, regardless of the rotational position of the valvemember 12 with respect to the valve body 20. As a result, the valvemember will selectively open and block the valve passages regardless ofa rotational position of the valve member relative to the valve chamber.

Referring to FIGS. 10A, 10B, and 11, the concept of sealing co-planarinlet and outlet ports 93, 95 regardless of the rotational position of avalve member 12 may be applied to any type of valve. In FIG. 10A, thevalve member is axially spaced apart from ports 93, 95 defined by avalve housing. In FIG. 10B, the valve member 12 is axially moved to aposition in a valve chamber 97 where the valve member seals against bothof the co-planar ports 93, 95. FIG. 11 illustrates that this sealingwill occur, regardless of the rotational orientation of the valve member12. The valve member is illustrated as a circular disk, but it may beany shape that covers the ports regardless of rotational orientation

FIGS. 4 and 5 illustrate another example of a valve 10. An actuatingarrangement for selectively moving the valve member 12 between the firstposition and the second position is not illustrated in FIGS. 4 and 5.Any suitable integral actuating arrangement may be incorporated into thevalve 10, or any discrete actuating arrangement may be coupled to thevalve to move the valve member between the first and second positions.Examples of suitable actuating arrangements include, but are not limitedto pneumatic actuators, hydraulic actuators, and electric actuators.

In the embodiment illustrated by FIGS. 4 and 5, the valve member 12includes a sealing portion 130, an actuation portion 132, and a ventingportion 134. The sealing portion 130 is disk-shaped and extends radiallyoutward of the actuation portion 132, and the venting portion 134. Theillustrated sealing portion 130 includes a flat sealing face 136. Theventing portion 134 is a cylindrical shaft that includes a longitudinalvent passage 138 and a transverse vent passage 139. In the illustratedembodiment, the venting portion 134 is axially aligned with a centralaxis 140 of the valve member 12. The venting portion 134 includes anannular vent seal recess 141. An annular vent sealing member 143 isdisposed in the recess 141.

In the embodiment illustrated by FIGS. 4 and 5, the valve chamber 24 isa cylindrical chamber. A cylindrical passage 152 is defined in the valvebody 20. A frustoconical sealing surface 156 extends from the valvechamber 24 to the chamber 152. In the illustrated embodiment, thediameter of the sealing surface 156 decreases from the valve chamber 24to the chamber 152. In the embodiment illustrated by FIGS. 4 and 5, thecylindrical chamber 152 and the frustoconical sealing surface 156 isdefined by a member 157 positioned in the valve body 20. A cylindricalvent opening 158 extends through the valve body to the valve chamber 24.The valve body includes a seal recess 182 that is disposed around aninlet passage opening 183. An annular inlet seal member 184 is disposedin the seal recess 182. The valve body includes a seal recess 186 aroundan outlet passage opening 188. An annular outlet seal member 190 isdisposed in the seal recess 186. In this example, the inlet and outletseal members are fixed with respect to the inlet passage and the outletpassage respectively. In another embodiment, the inlet and outlet sealmembers may be fixed to the sealing portion 130, instead of the valvebody.

In the embodiment illustrated by FIGS. 4 and 5, the valve member 12 isdisposed in the valve body, such that the sealing portion 130 isdisposed in the valve chamber 24, the actuation portion 132 extendsthrough the cylindrical passage 152, and the venting portion 134 extendsthrough the cylindrical vent opening 158.

In the embodiment illustrated by FIGS. 4 and 5, the inlet passage 14 andthe outlet passage 16 extend through both the manifold member 22 b andthe valve body 20. The manifold member includes a cylindrical ventchamber 176. The vent passage 18 extends from the vent chamber 176 outof the manifold member 22 b. The cylindrical vent portion 134 extendsinto the cylindrical vent chamber 176. The manifold member includes aninlet seal recess 189. An annular inlet seal member 185 is disposed inthe seal recess 189 to provide a seal between the valve body and themanifold member to inhibit leakage out of the inlet passage. Themanifold member includes an outlet seal recess 187. An annular outletseal member 191 is disposed in the seal recess 187 to provide a sealbetween the valve body and the manifold member to inhibit leakage out ofthe outlet passage.

In the example illustrated by FIGS. 4 and 5, o-rings provide a sealbetween each of the parts of the valve 10. An o-ring 192 provides a sealbetween the valve member 12 and the member 157. An o-ring 194 provides aseal between the valve member valve body 20 and the member 157. Ano-ring 195 provides a seal between the valve member 12 and the valvebody 20. An o-ring 196 provides a seal between the valve member 12 andthe manifold member 22 b.

FIGS. 4 and 5 illustrate operation of the valve. In the positionillustrated by FIG. 4, the flat sealing face 136 engages both the inletseal member 184 and the outlet seal member 190 to block both the inletpassage 14 and the outlet passage 16. In this position, the valvechamber 24 is open to the vent passage 18. Any fluid that is in thevalve chamber 24 can escape through the passage 139 and the vent passage138. In the position illustrated by FIG. 5, the flat sealing face 136 isspaced apart from both the inlet seal member 184 and the outlet sealmember 190. Fluid may flow from the inlet passage 14, into the valvechamber 24, and out the outlet passage 16. In this position, the ventseal member 143 provides a seal between the frustoconical sealingsurface 156 and the valve member 12 to block the flow of fluid from thevalve chamber 24 to the passage 139 and the vent passage 18.

In the embodiment illustrated by FIGS. 4 and 5, the valve member 12 mayrotate with respect to the valve body 20 without effecting operation ofthe valve 10. When the valve member is in the position illustrated byFIG. 4, the sealing portion 30 will block the inlet passage and theoutlet passage, regardless of the rotational position of the valvemember 12 with respect to the valve body 20. When the valve member is inthe position illustrated by FIG. 5, the vent seal member 143 will blockthe vent passage, regardless of the rotational position of the valvemember 12 with respect to the valve body 20. As a result, the valvemember will selectively open and block the valve passages regardless ofa rotational position of the valve member relative to the valve chamber.

FIGS. 6 and 7 illustrate another example of a valve 10. A actuatingarrangement for selectively moving the valve member 12 between the firstposition and the second position is not illustrated in FIGS. 6 and 7.Any suitable integral actuating arrangement may be incorporated into thevalve 10, or any discrete actuating arrangement may be coupled to thevalve to move the valve member between the first and second positions.

In the embodiment illustrated by FIGS. 6 and 7, the valve member 12includes a seal member carrying portion 230, an actuation portion 232,and a venting portion 234. In the illustrated embodiment, the sealmember carrying portion 230 is disk-shaped and extends radially outwardof the actuation portion 232, and the venting portion 234. The sealmember carrying portion 230 includes internally threaded recesses 235,236. Elongated inlet and outlet sealing structures 237, 239 extend fromthe seal member carrying portion 230. In the illustrated embodiment, thesealing structures 237, 239 each include a shaft portion 241, a sealcarrying portion 243 disposed at an end of the shaft portion, and a sealmember 245 carried by the seal carrying portion. In the exampleillustrated by FIGS. 6 and 7, each shaft portion 241 includes a threadedend that engages the threaded recesses 235, 236 to connect the elongatedsealing structure to the valve member. The venting portion 234 is acylindrical shaft that includes a vent passage 238. In the illustratedembodiment, the venting portion 234 is axially aligned with a centralaxis 240 of the valve member 12. The venting portion 234 includes anannular vent seal recess 247. An annular vent sealing member 243 isdisposed in the recess 247.

In the embodiment illustrated by FIGS. 6 and 7, the valve chamber 24 isa cylindrical chamber. A cylindrical passage 252 is defined in the valvebody 20. A frustoconical sealing surface 256 extends from the valvechamber 24 to the passage 252. In the illustrated embodiment, thediameter of the sealing surface 256 decreases from the valve chamber 24to the chamber 252. In the embodiment illustrated by FIGS. 6 and 7, thecylindrical passage 252 and the frustoconical sealing surface 256 aredefined by a member 257 positioned in the valve body 20. A cylindricalvent chamber 258 is defined in the valve body. A cylindrical inlet sealmember passage 259 and a cylindrical outlet seal member passage 261 aredefined through the valve body 20 and are in communication with thevalve chamber 24.

In the embodiment illustrated by FIGS. 6 and 7, the valve member 12 isdisposed in the valve body, such that the elongated inlet and outletsealing structures 237, 239 are disposed in the cylindrical passages259, 261 respectively, the actuation portion 232 extends into thecylindrical chamber 252, and the venting portion 234 extends into thecylindrical vent chamber 258.

In the embodiment illustrated by FIGS. 6 and 7, the manifold memberincludes an inlet seal recess 283. An annular inlet seal member 285 isdisposed in the seal recess 283 to provide a seal between the valve bodyand the manifold member to inhibit leakage out of the inlet passage. Themanifold member includes an outlet seal recess 287. An annular outletseal member 291 is disposed in the seal recess 287 to provide a sealbetween the valve body and the manifold member to inhibit leakage out ofthe outlet passage. The manifold member includes a vent seal recess 293.An annular vent seal member 295 is disposed in the seal recess 293 toprovide a seal between the valve body and the manifold member to inhibitleakage out of the vent passage.

In the example illustrated by FIGS. 6 and 7, o-rings are provided toprovide seals between each of the parts of the valve 10. An o-ring 292provides a seal between the valve member 12 and the member 257. Ano-ring 294 provides a seal between the valve member valve body 20 andthe member 257. An o-ring 297 provides a seal between the valve member12 and the valve body 20.

FIGS. 6 and 7 illustrate operation of the valve. In the positionillustrated by FIG. 6, the elongated sealing structure 237 engages themanifold member to block the inlet passage 14, the elongated sealingstructure 239 engages the manifold member to block the outlet passage16. In this position, any fluid in the valve chamber 24 is open to thevent passage 18. Any fluid that is in the valve chamber 24 can escapethrough the vent passage 238. In the position illustrated by FIG. 7, thesealing structures 237, 239 are spaced apart from an inlet opening andan outlet opening respectively. Fluid may flow from the inlet passage14, into the valve chamber 24, and out the outlet passage 16. In thisposition, the vent seal member 243 provides a seal between thefrustoconical sealing surface 256 and the valve member 12 to block theflow of fluid from the valve chamber 24 to the vent passage 18.

FIGS. 8 and 9 illustrate another example of a valve 10. In theembodiment illustrated by FIGS. 8 and 9, the valve member 12 isassembled to piston 332, by an elongated shaft 334. In the embodimentillustrated by FIGS. 8 and 9, the elongated shaft 334 includes externalthreads 344 and the valve member 12 includes internal threads 345. Theexternal threads 344 engage the internal threads 345 to connect theelongated shaft 334 to the valve member 12. The valve member 12 includesinternally threaded recesses 335, 336, 337. Elongated inlet, outlet, andvent sealing structures 338, 339, 340 extend from the valve member 12.In the illustrated embodiment, the inlet and outlet sealing structures338, 339 each include a shaft portion 341, a seal carrying portion 343,and a seal member 385 carried by the seal carrying portion. The sealcarrying portion 343 is configured to orient the seal member toward thevalve member 12. In the illustrated embodiment, vent sealing structure340 includes a shaft portion 347, a seal carrying portion 349, and aseal member 351 carried by the seal carrying portion. The shaft 347 ofthe vent sealing structure is shorter than the shafts 341 of the inletand outlet sealing structures in the example. The seal carrying portion349 is configured to orient the seal member away from the valve member12. In the example illustrated by FIGS. 8 and 9, each shaft portion 341,347 includes a threaded end that engages the threaded recesses 335, 336,337 to connect the elongated sealing structure to the valve member.

In the embodiment illustrated by FIGS. 8 and 9, the valve chamber 24 isa cylindrical chamber. An inlet passage 382, an outlet passage 384, anda vent passage 386 extend through an end wall 388 of the valve body andform a portion of the inlet 14, the outlet 16, and the vent 18. Acylindrical piston chamber 348 is disposed in the valve body. A dividingwall 354 separates the valve chamber 24 and the piston chamber 348. Acylindrical valve member passage 352 extends through the dividing wall.A pneumatic control passage 360 is defined in the valve body.

In the embodiment illustrated by FIGS. 8 and 9, the valve member 12 isdisposed in the in the valve chamber 24, the piston 332 is disposed inthe piston chamber 348, and the elongated shaft 334 extends through thepassage 352. A spring 364 is constrained in the piston chamber 352between the piston 332 and the dividing wall 354. In the embodimentillustrated by FIGS. 8 and 9, the spring biases the valve member in thedirection indicated by arrow 366. The piston moves in the directionindicated by arrow 372 against the biasing force of the spring 364 whenfluid under pressure is applied to the piston chamber 348.

In the example of FIGS. 8 and 9, an actuating arrangement forselectively moving the valve member 12 between the first position andthe second position is integrated into the valve. It should also bereadily apparent that a discrete actuating arrangement may be coupled tothe valve to move the valve member between the first and secondpositions. In addition, any type of actuating arrangement could be usedto move the valve member between the first and second positions.

In the embodiment illustrated by FIGS. 8 and 9, the inlet passage 14,the outlet passage 16, and the vent passage 18 extend through both themanifold member 22 and the valve body 20. The inlet passage in themanifold member includes a chamber 383 that accommodates the inlet sealcarrying portion and the inlet seal member. The outlet passage in themanifold member includes a chamber (hidden, but similar to chamber 383)that accommodates the outlet seal carrying portion and the outlet sealmember.

In the example illustrated by FIGS. 8 and 9, o-rings (not shown) mayprovide seals between each of the parts of the valve 10. The o-rings andseal members disclosed in the various examples described by the presentapplication may be made from a wide variety of different materials.Examples of materials that may be used include, but are not limited to,PCTFE, Teflon, PTFE, Modified PTFE, Vespel, PEEK, Viton, FluorocarbonFKM, Kalrez, Simriz, Perfluoroelastomer, Buna, UHMWPE, EthylenePropylene, Silicone, Alfas, Nylon, Torlon, stainless steel, carbonsteel, alloy steel, monel, hastelloy, titanium, brass, aluminum,inconel, nickel, and any other structural metal or plastic.

FIGS. 8 and 9 illustrate operation of the valve. In the positionillustrated by FIG. 8, the elongated inlet sealing structure 338 engagesthe valve body end wall outer surface to block the inlet passage 14, theelongated sealing structure 339 engages the valve body end wall outersurface to block the outlet passage 16. The elongated vent sealingstructure 340 is spaced apart from the valve body end wall (above thevalve body end wall in the orientation illustrated by FIGS. 8 and 9).Any fluid that is in the valve chamber 24 can escape through the ventpassage. In the position illustrated by FIG. 9, the sealing structures338, 339 are spaced apart from the valve body. Fluid may flow from theinlet passage 14, into the valve chamber 24, and out the outlet passage16. In this position, the vent sealing structure 340 engages the valvebody end wall inner surface to block the to the vent passage 18.

While various aspects of the invention are described and illustratedherein as embodied in combination in the exemplary embodiments, thesevarious aspects may be realized in many alternative embodiments, eitherindividually or in various combinations and sub-combinations thereof.Unless expressly excluded herein all such combinations andsub-combinations are intended to be within the scope of the presentinvention. Still further, while various alternative embodiments as tothe various aspects and features of the invention, such as alternativematerials, structures, configurations, methods, devices, software,hardware, control logic and so on may be described herein, suchdescriptions are not intended to be a complete or exhaustive list ofavailable alternative embodiments, whether presently known or laterdeveloped. Those skilled in the art may readily adopt one or more of theaspects, concepts or features of the invention into additionalembodiments within the scope of the present invention even if suchembodiments are not expressly disclosed herein. Additionally, eventhough some features, concepts or aspects of the invention may bedescribed herein as being a preferred arrangement or method, suchdescription is not intended to suggest that such feature is required ornecessary unless expressly so stated. Still further, exemplary orrepresentative values and ranges may be included to assist inunderstanding the present invention however, such values and ranges arenot to be construed in a limiting sense and are intended to be criticalvalues or ranges only if so expressly stated.

1. A capless valve actuating arrangement comprising: a) a valve body; b)a piston; c) a valve member connected to the piston and disposed in thevalve body, wherein movement of the valve member is limited by the valvebody, and axial movement of the piston is limited by the valve member.2. The capless valve actuating arrangement of claim 1 wherein the valvebody includes a passage that extends between the piston and the valvemember and the piston is connected to the valve member by a shaftdisposed in the passage.
 3. The capless valve actuating arrangement ofclaim 1 wherein the valve member and piston are moveable between a firstposition and a second position, wherein the piston extends past the endof the valve body when the piston and the valve member are in the secondposition.
 4. The capless valve actuating arrangement of claim 3 whereina portion of the piston that extends past the end of the valve body hasa finish that differs from a valve body finish to provide a visualindication that the valve member and the piston are in the secondposition.
 5. The capless valve actuating arrangement of claim 3 furthercomprising a piston seal disposed between the piston and the valve body,wherein a portion of the piston that extends past the end of the valvebody includes a step that limits exposure of the piston seal to foreignobjects.
 6. A valve actuating arrangement comprising: a) a valve bodydefining a piston recess in an end of the valve body and a valve memberrecess defined in the valve member assembly body; b) a piston disposedin the piston recess; c) a valve member disposed in the valve memberrecess such that axial movement of the valve member is limited by thevalve body, the valve member being coupled to the piston such that axialmovement of the piston causes axial movement of the valve member andwherein axial movement of the piston in the piston recess is limited bythe valve member.
 7. The valve member assembly of claim 6 wherein thevalve body includes a passage that extends between the piston recess andthe valve member recess and the piston is coupled to the valve member bya shaft disposed in the passage.
 8. The valve member assembly of claim 6wherein the valve member and piston are moveable between a firstposition and a second position, wherein the piston extends past the endof the valve body when the piston and the valve member are in the secondposition.
 9. The valve member assembly of claim 8 wherein a portion ofthe piston that extends past the end of the valve body has a finish thatdiffers from a valve body finish to provide a visual indication that thevalve member and the piston are in the second position.
 10. The valvemember assembly of claim 8 further comprising a piston seal disposedbetween the piston and the valve body, wherein a portion of the pistonthat extends past the end of the valve body includes a step that limitsexposure of the piston seal to foreign objects.
 11. A method ofproviding a visual indication of a state of the valve comprising: a)applying a fluid pressure to a piston to move the piston from a firstposition; b) moving a valve member with the piston; c) stopping thevalve member to stop the piston at a second position, wherein the pistonextends out of a valve body when the piston is at the second position toprovide a visual indication of the state of the valve.
 12. The method ofclaim 11 further comprising providing a finish on a portion of thepiston that extends out of the valve body that differs from a valve bodyfinish.
 13. A valve assembly, comprising: a) a valve chamber; b) aninlet passage in communication with the valve chamber; c) an outletpassage in communication with the valve chamber; d) a vent passage incommunication with the valve chamber; e) a valve member disposed in thevalve chamber, the valve member being axially moveable between a firstposition and a second position; f) wherein flow between the inletpassage and the valve chamber is blocked, flow between the outletpassage and the valve chamber is blocked, and flow between the ventpassage and the valve chamber is open when the valve member is in thefirst position regardless of a rotational orientation of the valvemember in the valve chamber; g) wherein flow between the inlet passageand the valve chamber is open, flow between the outlet passage and thevalve chamber is open, and flow between the vent passage and the valvechamber is blocked when the valve member is in the second positionregardless of the rotational orientation of the valve member in thevalve chamber.
 14. The valve of claim 13 wherein the valve membercomprises an annular disk.
 15. The valve of claim 13 wherein an axis ofthe vent port is aligned with an axis of the valve member.
 16. The valveof claim 13 wherein an axis of the vent port is aligned with an axis ofthe valve chamber.
 17. A method of controlling fluid flow comprising: a)providing fluid to an inlet passage that is in communication with avalve chamber; b) positioning a valve member in a first axial positionin the valve chamber where fluid flow between the inlet passage and thevalve chamber is blocked, fluid flow between the outlet passage and thevalve chamber is blocked, and fluid flow between the vent passage andthe valve chamber is open regardless of a rotational orientation of thevalve member in the valve chamber; c) positioning the valve member in asecond axial position in the valve chamber where fluid flow between theinlet passage and the valve chamber is open, fluid flow between theoutlet passage and the valve chamber is open, and fluid flow between thevent passage and the valve chamber is blocked regardless of therotational orientation of the valve member in the valve chamber.
 18. Avalve assembly, comprising: a) a passage defining including a valvechamber; b) a passage defining member defining an inlet passage, anoutlet passage, and a vent passage, the valve flange member beingassembled with the valve body to close the valve chamber; b) a valvemember assembled in the valve chamber by inserting the valve member intothe valve chamber from an end of the valve body that the passagedefining is to be assembled to prior to assembly of the passage definingmember with the valve body; c) wherein the valve member blocks fluidflow between the inlet passage and the valve chamber, blocks fluid flowbetween the outlet passage and the valve chamber, and allows fluid flowbetween the vent passage and the and the valve chamber when the valvemember is in a first position in the valve chamber, and wherein thevalve member allows fluid flow between the inlet passage and the valvechamber, allows fluid flow between the outlet passage and the valvechamber, and blocks fluid flow between the vent passage and the and thevalve chamber when the valve member is in a second position in the valvechamber.
 19. A valve assembly, comprising: a) a valve body defining avalve chamber; b) a valve member disposed in the valve chamber, thevalve member being moveable between a first position and a secondposition; c) a passage defining member that defines an inlet passage, anoutlet passage, and a vent passage, d) an inlet seal member assembledwith the passage defining member such that the inlet seal surrounds theinlet passage; e) an outlet seal member assembled with the passagedefining member such that the outlet seal surrounds the outlet passage,wherein the valve member contacts the inlet seal member and the outletseal member to block flow between the inlet passage and the valvechamber and block flow between the outlet passage and the valve chamberwhen the valve member is in the first position, and wherein the valvemember is spaced apart from the inlet seal member and the outlet sealmember to allow flow between the inlet passage and the outlet passagewhen the valve member is in the second position.
 20. The valve of claim19 wherein the passage defining member defines a wall of the valvechamber.
 21. The valve of claim 19 wherein the passage defining memberand the valve body are discrete components.
 22. The valve of claim 19wherein the inlet and outlet seal members comprise o-rings that arestaked to the passage defining member.
 23. The valve of claim 19 whereinthe inlet and outlet seal members are replaced by removing the passagedefining member and replacing the passage defining member with a newpassage defining member that includes new inlet and outlet seal members.24. The valve of claim 19 wherein annular grooves that accept the inletand outlet seal members are defined in a face of the passage definingmember.
 25. The valve of claim 19 wherein the passage defining memberincludes a vent port boss that extends from a face of the passagedefining member.
 26. A method of replacing seal members of a doubleblock and bleed valve, comprising: a) removing a passage defining memberthat defines an inlet passage, an outlet passage, and a vent passage andincludes an inlet seal member assembled around the inlet passage and anoutlet seal member assembled around the outlet passage from a valvebody; b) assembling a new passage defining member with the valve body.27. A valve assembly, comprising: a) a valve body defining a valvechamber; b) a valve member disposed in the valve chamber, the valvemember being moveable between a first position and a second position; c)a passage defining member that defines an inlet passage, an outletpassage, and a vent passage, the passage defining member is coupled tothe valve body to close the valve chamber such that the inlet passage,the outlet passage, and the vent passage are in communication with thevalve chamber; d) wherein flow between the inlet passage and the valvechamber is blocked, flow between the outlet passage and the valvechamber is blocked, and flow between the vent passage and the valvechamber is open when the valve member is in the first position; e)wherein flow between the inlet passage and the valve chamber is open,flow between the outlet passage and the valve chamber is open, and flowbetween the vent passage and the valve chamber is blocked when the valvemember is in the second position.
 28. The valve of claim 27 wherein thepassage defining member defines a wall of the valve chamber.
 29. Thevalve of claim 27 further comprising an inlet seal that is fixed withrespect to the inlet passage and an outlet seal that is fixed withrespect to the outlet passage, wherein the valve member engages theinlet seal and the outlet seal when the valve member is in the firstposition.
 30. The valve of claim 27 wherein the valve member comprisesan annular disk.
 31. The valve of claim 27 wherein the valve memberselectively opens and blocks the valve passages regardless of arotational position of the valve member relative to the valve chamber.32. The valve of claim 27 wherein an axis of the vent port is alignedwith an axis of the valve member.
 33. The valve of claim 27 wherein anaxis of the vent port is aligned with an axis of the valve chamber. 34.The valve of claim 27 further comprising an elongated inlet sealingstructure extending from the valve member and an elongated outletsealing structure extending from the valve member, wherein the elongatedinlet sealing structure engages the passage defining member to seal theinlet passage and the elongated outlet sealing structure engages thepassage defining member to seal the outlet passage when the valve memberis in the first position.
 35. The valve of claim 27 further comprising avent sealing member disposed around a valve member shaft, wherein thevent sealing member provides a seal between the valve member and thevalve body when the valve member is in the second position to block flowbetween the valve chamber and the vent passage when the valve member isin the second position.
 36. The valve of claim 27 further comprising anelongated inlet sealing structure extending from the valve member and anelongated outlet sealing structure extending from the valve member,wherein the elongated inlet sealing structure engages a valve body outersurface to seal the inlet passage and the elongated outlet sealingstructure engages the valve body outer surface to seal the outletpassage when the valve member is in the first position.
 37. The valve ofclaim 27 further comprising an elongated vent sealing structureextending from the valve member, wherein the elongated vent sealingstructure engages a valve body inner surface to seal the vent passagewhen the valve member is in the second position.
 38. The valve of claim27 further comprising an elongated inlet sealing structure extendingfrom the valve member, an elongated outlet sealing structure extendingfrom the valve member, and an elongated vent sealing structure extendingfrom the valve member, wherein the elongated inlet sealing structureengages a valve body outer surface to seal the inlet passage and theelongated outlet sealing structure engages the valve body outer surfaceto seal the outlet passage when the valve member is in the firstposition, and the elongated vent sealing structure engages a valve bodyinner surface to seal the vent passage when the valve member is in thesecond position.
 39. A valve assembly, comprising: a) a valve chamberthat includes first and second coplanar ports; b) a valve memberdisposed in the valve chamber, the valve member being axially moveablebetween a first position and a second position; c) wherein the valvemember provides a seal with the first port and provides a seal with thesecond port when the valve member is in the first position regardless ofa rotational orientation of the valve member in the valve chamber; d)wherein the valve member allows flow through the first port and allowsflow through the second port when the valve member is in the secondposition regardless of the rotational orientation of the valve member inthe valve chamber.
 40. The valve of claim 39 wherein the valve membercomprises an annular disk.